Tea bags and apparatus for use in their manufacture



F.MORPURGO Filed Jan.

TEA BAGS AND APPARATUS FOR USE IN THEIR MANUFACTURE June 29, 1965 UnitedStates Patent U 3,191,355 TEA BAGS AND APPARATUS FOR USE IN THEIRMANUFACTURE Fulvio Morpurgo, Via Geneva 23, Trieste, Italy Filed Jan. 9,1961, Ser. No. 81,329 Claims priority, application Italy, Jan. 16, 1960,743/ 60 Claims. (Cl. 53-134) This invention comprises improvements in orrelating to tea bags and apparatus for use in their manufacture.

In this specification the expression tea bags is intended to cover bagsfor the infusion of not only tea, but other aromatic herbs and productswhich are commonly infused in filter bags. Tea and like products arecommonly sold at the present time in porous bags of paper or plasticfilm material, each of which contains a measured quantity of the tea orthe like which is to be infused and to which is attached a suspensionstring by means of which the bag can readily be held clear of the bottomof the vessel in which infusion is taking place and by means of whichwithdrawal from the hot infusion can readily be eifected.

Packing of tea bags mechanically is not in itself difiicult but thefixing of the string, which tends to trail from the bag in a looselength, olfers difiiculties in me chanical handling both during andafter its attachment. It is an object of the present invention tofacilitate the mechanical handling of strung tea bags.

According to the present invention a tea bag having a suspension stringis characterised by the fact that the greater part of the length of thesuspension string is packed inside the bag, with one end passed slidablythrough the seal of the bag and a sufiicient amount protruding to enableit to be pulled out. In the preferred form the string is formed withinthe bag into a zig-zag loop and the other end of the string from thatwhich passes slidably through the seal, is fixed to the material of thebag.

The string may pass through and be fixed in the seal at one corner ofthe bag and then follow its zig-zag course within the bag and passslidably through the seal near the mid-point of one side of the bag.

The invention includes apparatus for producing tea bags as abovedescribed. According to one feature of the invent-ion apparatus forfixing a suspension string in tea bags comprises in combination meansfor passing a ribbon of partly formed and filled tea bags past astringing station, with one side of the ribbon of bags open to form amouth for each bag as it arrives at the station, string-feeding meansfor feeding string to a point in line with the mouth of the bag at thefilling station, a stringguide for holding a bight of the string overthe mouth, a pronged pusher movable to push part of the bight into a bagat the stringing station, a retaining member for keeping back anintermediate part of the bight between the prongs, means for releasingsaid intermediate part before the prongs have fully entered the bag andsealing means to seal the ends of the bight of string into the mouth ofthe bag after it has been positioned by the prongs.

The following is a description by way of example of one form of tea bagin accordance with the invention and of apparatus for its production:

In the accompanying drawings, FIGURE 1 is a representation of a tea bagin accordance with the invention and FIGURE 2 is a diagrammatic sideelevation of ap paratus for its production.

Referring to FIGURE 1 this shows a bag a in which the tea or otherproduct is contained. The bag is formed of two pieces of heat-sealingfilter paper, the side and bottom edges of which are sealed toconstitute the bag. The width of the sealed margin is indicated by adotted Patented June 29, 1965 See line. The suspension string b is fixedbetween the two faces of .the bag at the point c which appears at thetop ringht-hand corner in the drawing; it forms a shape like the leter WWithin the bag and passes out between the two faces of the bag at dwhere there is a short free external length. The top or mouth of the bage is sealed upon the string in the portion lying above the upperhorizontal dotted line.

Such a bag, having only a short length of protruding string, is easilyhandled mechanically and can for example be packed by a machine in anouter envelope without difficulty, whereas the attachment of a longexternal string leads to difficulties not only in attachment but insubsequent handling when the string gets in the way. When the bag comesto be used, a pull on the protruding portion d of the string draws itlongitudinally through the seal e and allows the string to be used forsuspending the bag in the usual way. The essential parts of theapparatus for the production of bags as above described in connectionwith FIGURE 1, are shown in FIGURE 2. In relation to this figure itshould be understood that means for producing a series of bags from twowebs of heat-scalable filter paper by running them together, sealingbottom and side margins and filling them with measured quantities oftea, are well-known and form no part of this invention. In FIGURE 2 itis assumed that a series of bags a having side and bottom edges sealedand filled with tea, are coming from the filling apparatus in thedirection of the arrow x, the bags forming, in effect, a continuousribbon because they have not been sub-divided from one another. Theknown filling machine is provided with means for advancing the bags stepby step and the advance is continued step by step through the apparatusin FIGURE 2, past a stringing station w, a sealing station y andrasevering apparatus located upon the line 0, 0'. String b is fed from areel not shown through an aperture in a string feeder i and then passesover a string guide 11, which is movable horizontally between thepositions h and h. The string guide I: moves in synchronism with theseries of bags a when their feeding movement takes place and at the endof the feeding movement the string stretches from the feeder i to theguide h in the position shown in full line in the drawing. In thisposition the bight of string between i and I2 overlies a stationaryretaining member g. Above the bight of string is a two-pronged pusher 1which is capable of moving up and down along the line indicated by thetwo-headed arrow 2.

With the parts in this position, the pusher f is moved down and pressesthe bight of string into the bag a which is at the stringing station andas the centre of the string is retained by the retaining member gbetween the prongs, the string assumes a W formation. During thisoperation string is drawn through the aperture in the string feeder ifrom the reel. A little before the prongs reach the bottom of theirstroke the retaining member g is withdrawn endwise, releasing the midlepart of the string which had been held back and during the remainder ofthe down stroke of the prongs the centre of the zig-zag bight of stringis drawn into the bag and assumes the shape shown in chain lines in thefigure.

As soon as the prongs have brought the W shaped bight of string entirelywithin the bag, a pair of jaws m closes horizontally on the bag fromopposite sides at the position shown in chain lines at the stringingstation w. The pincer jaws m are recessed to avoid contact with theprongs 1 but they grip the sides of the bag on each side of the prongsand grip the string in its W formation tightly through the sides of thebag. It will beunderstood that the bulk of the tea which has been fedinto the bag previously will be lying in the bottom of the bag below thejaws m. As soon as the string is gripped by the jaws m the prongs f arewithdrawn to their uppermost position, the loop of string remaining heldin the shape into which it has been formed.

While the pr ngs f are being withdrawn the string guide h iswithdrawnendwise from beneath the string andreturned from the position hto the position 11 close beneath the string feeder i. With the parts inthis position and the jaws m closed the ribbon of bags is fed forwardone step .so that the bag from the stringing station w reaches thesealing station y. The string guide It moves forward to the position h"during this operation.

Theretaining member g now moves forward into operative' position againand the operations at the stringing station are repeated; Meanwhile,heated sealing jaws advance upon the upper margin of the bag at thesealing.

station. and press, upon the bag in the ,shaded area indicated at n. Thejaws then retreat to permit the next feeding movement of the bags andthe clamping jaws m are Opened and returned to the position shown inchain lines at the stringing station. i

A While the bag is being sealed at the sealing station y the cuttersoperating upon a line 0, o sever the next bag but one from the ribbon Itshould be noted that during all the, operations up to that'of severingthe bag the string remains. continuous. The short length of stringrequired to be left free of the bag is automaticallyprovided by the loopof-string which class in which a continuous ribbon of interconnectedtea.

bags of heat scalable flexible sheetmaterial, all having mouths openingthrough a single. mouth defining edge of the ribbon, is movedintermittently in the direction of its length past relatively spacedheatsealing and.cutting stations in uniform increments such that-each bagdwells at a predetermined location in advance of said heat sealingstation, the combination with .said filling and sealingapparatus ofapparatus forinsertingsuspension stringsinthe respective bags insuccession comprising, string guiding means for guiding string to apoint in linewiththe mouth of the bag at said location, astring guidefor holding a bight of the string over the mouth, a pronged pushermovable to push part of the bight into the'bagat the said location, aretaining member for keeping back an intermediate part of the bightbetween the, prongs of said pusher, said retaining'rnember beingretractable to, release said intermediate part before. the prongs havefully entered the bag, clamping means being provided to grip the stringin the zig-zag formation upon- Withdrawal of the said prongs, saidclamping means beingmovable with the feed movementof the-bags to holdthelstringwhile the ribbon of bags is fed to bring a fresh bag to saidlocation.

2 Apparatus as claimed-in claim 1 wherein the string guide for holdingthe bight over the mouth of the bag is movable from a string-receivingposition close to the string feedingimeans at one side of the mouth ofthe bag to a holding position at theother side of said mouth,

3. Apparatus as claimed in claim 2 wherein the movement of the stringguide is simultaneouswith the feed movement of the string of bags.

4. Apparatus as claimed in claim 1 wherein the pusher has two prongs, sothat in conjunction with the retaining member the string is formed intoa W shape in the bag.

5. In a tea bag filling and sealing apparatus of the class in which acontinuous ribbon of interconnected tea bags of heat sealable sheetmaterialall having mouths opening through a single-mouth definingedge ofthe ribbon, is moved. intermittently in the direction of its length pastrelatively spaced heat sealing and cutting stations in uniformincrements such that, each bag, dwells at a predetermined location inadvance. of said heat sealing: station, the combination with saidapparatus, of apparatus for inserting suspension strings-in. therespective bags comprising:

(a) string guiding means for guiding string from a source of supplyinthe plane ofthe mouth of each bag, said guiding means being fixedlylocated adjacent said mouth defining edge of the ribbon and at'saidpredetermined location,-

(b) a string guidedisposed for reciprocating movement along a pathparallel to, the movement of said ribbon adjacent the said mouthdefining edge thereof tocarry a bight of the string from said guidemeans in the direction of advance movement of the ribbon,

(c) a retaining member positioned adjacent saidmouth defining edge ofthe ribbon :at said predetermined location and between said ribbon andthe path of movement. of said string guide,

(d) a bifurcated pusher disposed for movementintoand from the mouths ofthe respective bags, said movement being normal to movement of saidstring guide and said ribbon and=in the plane of the latter, thefurcations of said pusher projecting toward said ribbon and spaced aparton opposite sides of said retaining memberfor free movement pastsaidmem-.

her to carry loops of string into-each mouth aroundand onoppositesidesof said retainer-member, (e) said retainer member being-movable fordisengagement from said string during the projection movemerit of saidpusher, (f) clamp jaws mounted on opposite sides of the said ribbon atsaid predetermined location for movement into clamping engagement withthe ribbon and the string therein, to retain the string in place duringwithdrawal of said furcations of the pusher,

(g) said jaws and said string guide being disposedfor movement with saidribbon from said predetermined location to said sealing station.

References Cited by the Examiner FRANK E. BAILEY, Primary Examiner.

ABRAHAM WINKELSTEIN, TRAVIS s, MCGEHEE,

Examine s,

1. IN A TEA BAG FILLING AND SEALING APPARATUS OF THE CLASS IN WHICH ACONTINUOUS RIBBON OF INTERCONNECTED TEA BAGS OF HEAT SEALABLE FLEXIBLESHEET MATERIAL, ALL HAVING MOUTHS OPENING THROUGH A SINGLE MOUTHDEFINING EDGE OF THE RIBBON, IS MOVED INTERMITTENTLY IN THE DIRECTION OFITS LENGTH PAST RELATIVELY SPACED HEAT SEALING AND CUTTING STATIONS INUNIFORM INCREMENTS SUCH THAT EACH BAG DWELLS AT A PREDETERMINED LOCATIONIN ADVANCE OF SAID HEAT SEALING STATION, THE COMBINATION WITH SAIDFILLING AND SEALING APPARATUS OF APPARATUS FOR INSERTING SUSPENSIONSTRINGS IN THE RESPECTIVE BAGS IN SUCCESSION COMPRISING, STRING GUIDINGMEANS FOR GUIDING STRING TO A POINT IN LINE WITH THE MOUTH OF THE BAG ATSAID LOCATION, A STRING GUIDE FOR HOLDING A BIGHT OF THE STRING OVER THEMOUTH, A PRONGED PUSHER MOVABLE TO PUSH PART OF THE BIGHT INTO THE BAGAT THE SAID LOCATION, A RETAINING MEMBER FOR KEEPING BACK ANINTERMEDIATE PART OF THE BIGHT BETWEEN THE PRONGS OF SAID PUSHER, SAIDRETAINING MEMBER BEING RETRACTABLE TO